1. Field of the Invention
This document relates to a liquid crystal display, and more particularly, to a backlight assembly for a liquid crystal display with a U-shaped lamp.
2. Discussion of the Related Art
The liquid crystal display displays an image corresponding to a video signal in a liquid crystal display panel by adjusting the light transmittance of liquid crystal using an electric field. In a passive light emitting liquid crystal display, a backlight used as a light source is mounted at the rear of a liquid crystal panel, and because mounting of the backlight at the rear may increase the thickness, weight, and power consumption of the liquid crystal display, research regarding improving backlights is ongoing.
In general, a so-called backlight used as a light source of the liquid crystal display includes a cylindrical fluorescent lamp, and backlights may include two types: a direct backlight type and a light guiding plate type.
In the direct backlight type, a fluorescent lamp is arranged in a flat plane, but because a shape of the fluorescent lamp is visible on the liquid crystal panel, a light scattering means should be arranged so as to uniformly distribute light from the fluorescent lamp, so there is a limit in the decrease in thickness possible.
Further, as the size of a panel increases, the area of a light emitting plane of the backlight increases. When the size of the direct backlight increases, the light emitting plane is not uniform if light scattering means is not of sufficient thickness, so the light scattering means needs to have a sufficient thickness in order to have a uniform display.
For a light guiding plate type backlight, a fluorescent lamp is provided at an edge of the display, and light is distributed across the entire plane using the light guiding plate. As a result, from the fluorescent bulb the brightness of the display is low. Further, in order to uniformly distribute light, an advanced optical design technology and processing technology for the light guiding plate are required.
Because the direct backlight type and the light guiding plate type have advantages and disadvantages, the direct backlight type backlight is generally used in a liquid crystal display where brightness is more important than the thickness of a screen, and the light guiding plate type backlight is generally used in a liquid crystal display where thickness is more important than brightness such as in a notebook PC or a monitor for a PC.
Recently, a method of manufacturing a lamp in a U-shape has been developed, and in the U-shaped lamp, because a distance between electrodes at both ends is short, a tube current can be easily measured and brightness can be accurately measured.
FIG. 1 is an exploded perspective view of a liquid crystal module including a backlight with a general U-shaped lamp.
Referring to FIG. 1, a general liquid crystal module includes a liquid crystal panel 100, a backlight assembly 150, and a top cover 160.
The liquid crystal panel 100 includes a lower substrate 110, a upper substrate 120, liquid crystal (not shown), a gate tape carrier package (TCP) 130, a gate printed circuit board (PCB) 135, a data TCP 140, and a data PCB 145.
The backlight assembly 150 includes an optical sheet 151, a diffusion plate 152, a support main 153, U-shaped lamps 154, and a reflecting plate 155.
The U-shaped lamps 154 irradiate light, and the reflecting plate 155 is below the lamp 154 to reflect light emitted below the lamp 154 toward the upper diffusion plate 152.
After light irradiated from the U-shaped lamp 154 and light reflected by the reflecting plate 155 is diffused to have uniform brightness by the diffusion plate 152, the combined light is focused by the optical sheet 151 such as a prism.
The elements of the backlight assembly 150 described above are in an internal space defined by coupling the support main 153 and the bottom cover 170, and the bottom cover 170 is also coupled to the top cover 160 to form a liquid crystal module.
FIG. 2 is a view illustrating a backlight assembly in the related art in which U-shaped lamps are used. FIG. 3 is a view illustrating the U-shaped lamp of FIG. 2 inserted into an inserting part formed in a side supporter 220.
Referring to FIG. 2, the backlight assembly in the related art using the U-shaped may include a lamp housing 210, a side supporter 220, and a U-shaped lamps 230. The backlight assembly shown in FIG. 1 is described with the optical sheet 151, the diffusion plate 152, the support main 153, and the reflecting plate 155. However, for convenience, in FIG. 2, only the lamp housing 210, the side supporter 220, and the U-shaped lamp 230 are described.
As shown in FIG. 2, in the backlight assembly in the related art using the U-shaped lamp, the lamp housing 210 may be a bottom cover and when one side of the lamp housing 210 is opened, the side supporter 220 is fastened to the lamp housing 210. The side supporter 220 has a structure for inserting the U-shaped lamp 230, but does not fix the U-shaped lamp 230.
Specifically, referring to FIG. 3, when directly inserting and fixing the U-shaped lamp 230 into the side supporter 220, there is a problem where the lamp 230 is not stably fixed due to a tolerance of the lamp 230 and a tolerance of the inserting part 221 within the side supporter 220. Particularly, in a liquid crystal display for a TV, there is a problem that sound vibration may be generated in the lamp 230 by sound from a speaker in the TV.